1. Field of the Invention
The present invention relates to telescopic sights for firearms, and particularly to a tool or gauge for aligning a telescopic sight with an associated firearm so the telescopic sight and reticle therein is square with the horizontal lateral and vertical axes of the firearm.
2. Description of the Related Art
The telescopic sight for rifles and other firearms has proven to be of great assistance in the quest by marksmen for greater accuracy. Indeed, many of the various factors that are considered by expert shooters can only be compensated for by an accurately aligned telescopic sight or “scope” on the firearm. It should also be noted that while telescopic sights were first developed for rifles firing a single round over a relatively long distance, telescopic sights or scopes have been installed on handguns and shotguns as well, and the need exists for accurate alignment of the scope with these types of firearms as well.
There are various aspects of scope alignment that must be considered. Obviously, the optical axis of the scope must be aligned with the barrel of the firearm. This type of alignment is handled by different tools and gauges than the telescopic sight alignment tool of the present invention, and the tool of the present invention does not measure or determine the alignment of the optical axis of the scope with the barrel of the firearm. However, another consideration is the parallelism between the horizontal and vertical crosshairs of the reticle of the scope, and the corresponding horizontal lateral and vertical axes of the firearm. It will be seen that if the vertical axis of the scope is not aligned with or at least parallel to the vertical axis of the firearm upon which the scope is installed, the vertical axis of the firearm will not be truly vertical when the crosshairs of the scope reticle are truly vertical and horizontal. As virtually all scopes are adjustable for elevation (bullet drop) for the distance between the firearm and the target, it will be seen that any angularity between the scope and the firearm will tend to cant the plane of the elevation adjustment from the vertical, leading to unintended lateral displacement of the round when it hits the target. U.S. Pat. No. 6,862,833 issued on Mar. 8, 2005 to Frederick W. Gurtner provides a good explanation of this phenomenon, as well as a tool for measuring and correcting for non-parallelism between the vertical and horizontal axes of the scope and firearm.
Numerous other devices have been developed to measure and accommodate any lack of parallel between the horizontal and vertical axes of the scope and firearm. An example of such is found in German Patent Publication No. 3,401,855 published on Jul. 25, 1985 to Walther GMBH. This device comprises a sight ring that is installed about the ocular of the scope. The ring is partially filled with a colored liquid and acts somewhat as a bubble level in allowing the marksman to align the axes of the scope, and thus the attached firearm, in accordance with the sight ring.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus, a telescopic sight alignment tool solving the aforementioned problems is desired.